Ozone Layer/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim is standing in his living room. Moby joins him. Moby has a large hole in his stomach, and his inner workings are visible. TIM: Yikes! You'd better get that checked out, Moby. I'll handle this letter. Tim reads from a typed letter. TIM: Dear Tim and Moby, what is causing the ozone layer to deteriorate and how will it affect us? From, Eman. Ozone is a gas made up of molecules with three oxygen atoms. The kind of oxygen we breathe has two. An animation shows a single ozone molecule, made of three oxygen atoms. TIM: The ozone layer is a part of Earth's atmosphere where a high concentration of this gas protects us from the sun's powerful ultraviolet radiation. An animation shows the earth, its atmosphere with the ozone layer, and the sun from space. The sun's radiation is represented by squiggly lines. Earth's ozone layer blocks the sun's radiation as Tim describes. TIM: Too much UV radiation is bad for a lot of reasons. It can cause skin cancer, eye problems, and weaken your immune system. An animation of a human silhouette displays eyes, skin, and internal organs damaged by UV radiation. TIM: It's also harmful to plants and animals, upsetting the balance of the food chain. An animation demonstrates a food pyramid. Shrimp and underwater plants are on the bottom level. Small fish are on the level above it. Larger fish are on the level above that, and there is a bear at the top level. TIM: You may have heard of the hole in the ozone layer. Ozone is constantly being produced and destroyed in the atmosphere, but the total amount is basically stable. In the nineteen-eighties, scientists noticed a drastic thinning of the ozone over Antarctica, causing the destruction of nearly seventy percent of the ozone layer normally found there. An animation shows the earth's southern hemisphere from above. A hole appears and revolves over Antarctica. Moby pushes his face into view, then pulls it back. TIM: It's kind of like that hole in Moby. Moby pokes a wire into the hole in his stomach. It touches metal, and there is a spark. TIM: Without his protective covering, Moby's insides are vulnerable to things that could really mess him up. That's why Moby's off getting repaired right now and why it's important for us to know what's going on with this ozone thing. I'm not sure what happened to Moby, but the ozone depletion is caused by the release of certain chemical compounds into the air. Compounds such as chlorofluorocarbons, or CFCs, and other ozone-depleting substances, were used in refrigerators, spray cans, and other household stuff. Images show a refrigerator and an aerosol can. TIM: CFCs take a few years to get up to the stratosphere, but once there, radiation from the sun triggers a series of reactions that causes ozone to break down. An animation shows chlorofluorocarbons rising to the top of the atmosphere, with the sun triggering the process that Tim describes. TIM: So are we doomed to lose the entire ozone layer and live in a world of never-ending sunburn? An animation shows Cassie and Rita in chairs at the beach. Both are wearing big, floppy hats, shirts, and sunscreen. Both have very red skin. TIM: Luckily, people realized this could be a problem, so in 1987, many nations signed a treaty called the Montreal Protocol, promising to reduce their use of CFCs and other ozone-depleting substances. An image shows a group of people of various races with smiley faces. TIM: Today, over one hundred ninety countries have signed a new version of the treaty, agreeing to stop all CFC production. The group of smiley-faced people becomes larger. Text reads: CFCs. The No-symbol appears over the text. TIM: In the United States, the Environmental Protection Agency oversees a number of programs designed to help the ozone layer. A map shows the United States. TIM: People can help by making sure that the folks who repair their air conditioners and refrigerators are EPA-certified, so tell your parents. Moby walks up to Tim. A flat piece of metal has been bolted over the hole in his stomach, not quite covering it. TIM: Um, wow. Moby, that's great. Tim is not enthused about Moby's repair job. MOBY: Beep. TIM: Why can't we just patch up the ozone layer like you, Moby? Unfortunately, we can't make enough ozone to replace what's been lost. The good news is that ozone is produced naturally, so if we stop making ozone-depleting substances like CFCs; the ozone layer could be restored to normal conditions in as little as fifty years. An animation shows the ozone layer over Antarctica closing. TIM: In fact, scientists have recently confirmed that they've started to see some recovery in the amount of ozone in the atmosphere. It's really important that people know about the ozone, though, so the whole world will stop producing the chemicals that cause its depletion. MOBY: Beep. Moby taps the plate on his stomach. TIM: I don't think they want to see a movie about that, Moby. MOBY: Beep. Tim sighs. Category:BrainPOP Transcripts